Rotatable buoy for mooring vessels

ABSTRACT

A buoy for mooring vessels such as tankers is encircled by a relatively rotatable ring to which are secured a plurality of anchor chains so that the buoy can rotate about a vertical axis within and relative to the ring. At least one coupling member in the form of a rigid arm is integrally and rigidly secured to the buoy for rotation therewith. The end of the arm remote from the buoy is secured to the moored vessel for relative vertical swinging movement about a horizontal pin. A pipeline on the ocean floor enters the buoy and passes through the arm to the moored vessel.

United States Patent 1191 Van Heijst 5] July 16, 1974 ROTATABLE BUOY FORMOORING 3,735,435 5/1973 Mikulicic et a1. 9/8 P VESSELS FOREIGN PATENTSOR APPLICATIONS Inventor; Willem J Van i Monte 1,260,034 3/1961 France114/230 Carlo, Monaco 6,600,321 7/1966 Netherlands 114/230 [73]Assignee: N.V. Industrieele Handelscombinatie, Rotterdam, PrimaryNetherlands Assistant ExaminerDonald W. Underwood An ,A t, F -Y &Th [22]Filed: June 1, 1973 gen [21] Appl. No.: 366,243 [57] ABSTRACT A buoy formooring vessels such as tankers is encir- [30] Foreign ApplicationPriority Data cled by a relatively rotatable ring to which are securedJune 9, 1972 Netherlands 7207903 a plurality and! chains that the W canA tate about a vertical axis within and relative to the 52 US. Cl. 9/8 P2- At least one coupling member in the form of a 51 1111.01 .Q B63b21/52 rigid arm is integrally and rigidly Secured to the y 58 Field ofSearch 9/8 R, s P; 114/230 for rotation therewith The end of the armremote from the buoy is secured to the moored vessel for rela- 5References Cited tive vertical swinging movement about a horizontalUNITED STATES PATENTS pin. A pipeline on the ocean floor enters the buoyand passes through the arm to the moored vessel. 3,354,479 11/1967Koppenol et al..... 9/8 P 3,414,918 12/1968 Petrie et al. 9/8 P 3Claims, 1 Drawing; Figure PATENTEDJUL 1 e 1914 ROTATABLE BUOY FORMOORING VESSELS The present invention relates to improvements in, orrelates to, a buoy with an associated mooring arrangement.

Such a buoy with an associated mooring arrangement is known from theDutch Patent application No: 66.0032l, now laid open to publicinspection, and which buoy is anchored by a number of anchors and anchorchains. The associated mooring arrangement is coupled to the buoy by anumber of rigid members which serve to hold the mooring arrangement offfrom the buoy. Particular ones of these coupling members, on the onehand are each pivotably hinged on a horizontally disposed pin affixed tothe mooring arrangement; and others of these coupling members, on theother hand, are coupled to the buoy in such a manner that the mooringarrangement can swing about the axis of a vertically arranged shaft onthe buoy.

In this known arrangement of a buoy with its associated mooringarrangement, the rigid coupling members are pivotably hinged withrespect to a turn-table arranged on the buoy by means of a horizontallydisposed shaft affixed to the turn-table so as to couple the buoy to themooring arrangement. In certain instances a ship, such as a tanker, mayconstitute the mooring arrangement and to which yet another ship, ortanker, can bemoored.

Buoys with associated mooring arrangements of this type are subjected totidal and weather conditions which require the buoy to have aconsiderable inherent stability to cope with the forces exercisedthereon by the mooring arrangement, and which forces tend to tip thebuoy. This means that the buoy needs to havea relatively large mass withthe result that the forces manifesting themselves in the rigid couplingmembers coupling the buoy to the mooring arrangement.i.e., a ship, or atanker, are also of con siderablemagnitude.

The present invention therefore is directed to the provision of a buoywith an associated mooring arrangement in which considerably lesserloads are presented thereto. This object is achieved, according to thepresent invention, in that the buoy and the rigid couling members whichhold-off the mooring arrangement form a rigid integral unit, andinasmuch that the anchor chains are affixed, at one end thereof, to aring rotatably arranged on and with respect to the buoy. With such anarrangement the buoy no longer needs to have an inherent stability. Thedisplacement of the buoy does not need; to then be greater than thatwhich is necessary for the bouyancy thereof to support the anchor chainsand to effect transmission of the forces required for the mooring of theship, or tanker, and other means moored thereto, to the anchors. Thebuoy is coupled to the mooring arrangement in a manner which may belikened to the manner in which a wheel barrow is held by its user i.e.,the single wheel of the wheel barrow may be likened to the buoy, the twohandles thereof to the coupling members, and the mooring arrangement tothe user of the wheel barrow and such that any lateral roll of the shipis transferred to the buoy via the rigid coupling members in the sameway that any lateral tilting of the barrow by the user will betransferred through the handles thereof to the single front wheel whichhas, more or less, only point contact with the ground. Thus the rigidcoupling effect of mooring arrangement to the buoy has the same effectas the rigid coupling effect between the user of the wheel barrow andthe single wheel thereof. This rigid coupling effect, between buoy andmooring arrangement, is made possible by the form and dimensions towhich the buoy is designed and by which the buoy and mooring arrangementlaterally roll together. The design of the buoy being such that theforce of inertia of the buoy to be overcome is relatively small sincethe form is such that it offers very little resistance to the action ofwaves and tide thereon. A buoy having the underwater portion thereof ofa somewhat streamlined or smooth form may be employed without objection.In accordance with the present invention it is preferable that the rigidcoupling member, or members, holding the buoy off from the ship shouldbe buoyant, such that when the mooring arrangement casts-off from thebuoy the latters buoyancy should remain stable and relativelyundisturbed.

It will be noted that in US. Pat. No. 3,354,479 a buoy having aturn-table is well-known, and in which a mooring arm extending therefromis in the form of a girder provided with floats. This mooring arm isrotatably coupled to the buoy via a vertical shaft. The mooring armcomprises two parts which are hingeably coupled to one another, andwhich hingeing arrangement per mits pivoting of the two parts about theaxis of a horizontally disposed shaft, and in which that portion of themooring arm, which diverges at the end remote thereof from the buoy, isaffixed to the side of the tanker. The tanker itself is moored to thebuoy by means of cables shackled to the turn-table thereof. Shouldrelative movement occur between the tanker and the buoy through wind andwaves this will lead to the imposition of a very heavy load on thevertically disposed hinge about the axis of which pivoting takes placebetween the mooring arm and the buoy.

It will be noted further from US. Pat. No. 3,335,690 that a mooringarrangement is known which has, extendingfrom the stem or bow thereof, asupport structure having arranged thereon a ring which, relative to thesupport structure, is rotatable and to which ring the anchor chains areshackled. Rise and fall of the mooring arrangement due to tidal swell orweather conditions leads to the imposition of very heavy loads on theanchor chains, the ring and the bearings therefor.

In view of the foregoing disadvantages of known mooring arrangements, inthe present invention there is provided accordingly:

A buoy with an associated mooring arrangement anchored by means of anumber of anchors and the chains therefor in which the mooringarrangement and the buoy are coupled by one or more rigid couplingmembers holding the mooring arrangement off from the buoy and which saidone or more coupling members are, on one hand, each pivotably mounted ona horizontally disposed pin on the mooring arrangement; and which eachsaid one or more coupling members, on the other hand, is coupled to thebu-oy in such a manner that the mooring arrangement can swing about theaxis of a vertical shaft on the buoy; and in which the said buoy andmooring arrangement form an integral and rigid unit, and the anchorchains are affixed to a ring arranged for rotation about the verticalaxis of a shaft on the buoy.

The FIGURE illustrates a schematic cross sectional view of the presentinvention.

The invention will be better understood from the following descriptionread with reference to the accompanying drawing, and in which themooring arrangement is in the form of a tanker 1. The buoy comprises afloat 2 of relatively small size having two integral arms, forming thecoupling members 3, which are pivotably arranged on a pin 4 extendingtransversely through the bow of the tanker, or each on a pin extendingtransversely from the sides of the bow.

A ring 6 is rotatably arranged on the body of the buoy 2 by means of abearing 5, and'which ring is provided with conical recesses 7 foraccomodating the members 8 of the anchor chains 9 for retention therein.

A pipe-line or hose 15, supported by the arms or coupling members 3, iscoupled to a pipeline 13 supported by a suitable foundation on the seabed via an intermediate pipe-line provided with universal joints 10, 11and 12 or, alternatively, ball-and-socket joints. The pipeline or hose13 can rotate or swing about the vertical axis of the buoy with the armsor coupling members 3 and with respect to the intermediate pipe-line bythe provision of rotatable coupling 14 therebetween.

What we claim is:

l. A buoy encircled by a ring, anchor chains secured to the ring, meansinterconnecting the buoy and the ring for rotation of the buoy relativeto the ring about a vertical axis, at least one arm fixedly secured toand rotatable with the buoy and extending laterally from the buoy, andmeans for interconnecting the end of the arm remote from the buoy to avessel for vertical swinging movement of the arm and vessel relative toeach other about a horizontal axis.

2. A buoy as claimed in claim 1, said arm being buoyant.

3. A buoy as claimed in claim 1, and conduit means extending throughsaid buoy and arm, and means interconnecting a portion of said conduitmeans with said buoy for rotation of said buoy about an upright axisrelative to said conduit means.

1. A buoy encircled by a ring, anchor chains secured to the ring, means interconnecting the buoy and the ring for rotation of the buoy relative to the ring about a vertical axis, at least one arm fixedly secured to and rotatable with the buoy and extending laterally from the buoy, and means for interconnecting the end of the arm remote from the buoy to a vessel for vertical swinging movement of the arm and vessel relative to each other about a horizontal axis.
 2. A buoy as claimed in claim 1, said arm being buoyant.
 3. A buoy as claimed in claim 1, and conduit means extending through said buoy and arm, and means interconnecting a portion of said conduit means with said buoy for rotation of said buoy about an upright axis relative to said conduit means. 